1. The Field of the Invention
This invention relates generally to enhanced television, such as a video stream compressed according to a Moving Pictures Expert Group (MPEG) standard, and a corresponding content stream of pages in a markup language format. More particularly, the invention relates to rewinding and fast-forwarding within the video stream and the corresponding content stream.
2. Background and Relevant Art
The video and computer industries are working towards achieving convergence in the television space. This means, among other things, that television and computer content will become integrated. One type of convergence is enhanced television. In enhanced television generally, a compressed video stream is enhanced with a corresponding content stream. The television viewer can watch the video stream as he or she normally watches television, but can also interact with the content stream. For example, while a baseball game is being displayed within the video stream, the content stream may show some information regarding the player currently at bat. The viewer may be able to select hyperlinks within the content stream to view other information regarding the player or his team, or other information. The ability of the viewer to select links within the content stream enhances the television-viewing experience.
Video streams are usually compressed according to known MPEG standards, such as the MPEG-1 or MPEG-2 standards. Content streams can be a series of pages in a known markup language that correspond to the video streams. For example, the markup language may be the HyperText Markup Language (HTML), the eXtended Markup Language (XML), or another markup language. Content streams that have pages according to a known markup language have the benefit of being interactive, because links on the pages can be selected by users. Pages formatted according to markup languages can also easily be viewed. For example, web browser computer programs and web browser operating system components that permit viewing of such pages are widely available.
A disadvantage with enhanced television in general is that it does not provide for rewinding and fast-forwarding within both the compressed video stream and the corresponding content stream. Skipping within the compressed video stream alone is difficult. Since the video stream is compressed, it is difficult to go back within the stream. Corresponding rewinding and fast-forwarding within the content stream makes the problem more difficult. Skipping within the content stream, for instance, should be aligned with skipping within the video stream. For these and other reasons, there is a need for the present invention.